Follow-up echocardiographic changes in children and youth aged <25 years with latent rheumatic heart disease: A systematic review and meta-analysis of global data.

Objectives: To estimate progression, regression and persistence rates for borderline and mild-definite latent RHD in children and youth diagnosed at age < 25 years.

Methods: A review was conducted in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines. Electronic databases were searched for latent RHD echocardiography follow-up studies which used World Heart Federation diagnostic criteria. A meta-analysis of outcomes was conducted for borderline and mild-definite disease subcategories.

Results: Data for 1618 individuals from 12 studies were included. For borderline cases, 48.51% regressed (95%CI 45.10-51.93), 13.99% progressed (95%CI 9.72-18.25), and 38.61% had persistent (unchanged) disease at follow-up (95%CI 29.68-47.54). For mild-definite cases, 34.01% regressed (95%CI 28.88-39.15), 8.06% progressed (95%CI 3.65-16.90), and 60.23% had persistent disease (95%CI 55.08-67.38).

Conclusions: Borderline and mild-definite latent RHD show variable evolution following initial diagnosis. While 8% of mild-definite and 14% borderline cases had signs of disease progression at follow-up, a third of mild-definite and half of borderline cases had disease regression, even with sub adequate antibiotic prophylaxis. The significant variability between study cohorts suggests latent RHD natural history is likely variable between different endemic regions globally. Future research is needed to identify those individuals who would most benefit from antibiotic prophylaxis and determine regional natural history of latent RHD.